Field
The invention relates to biologically active compounds, compositions comprising the same, and methods of using such biologically active compounds and compositions for the treatment of cancer and other diseases.
Description of the Related Art
Promising new cancer therapeutics include the dolastatins and synthetic dolastatin analogs such as auristatins (U.S. Pat. Nos. 5,635,483, 5,780,588, 6,323,315, and 6,884,869; Shnyder et al. (2007) Int. J. Oncol. 31:353-360; Otani, M. et al. Jpn. J. Cancer Res. 2000, 91, 837-844; PCT Intl. Publ. Nos. WO 01/18032 A3, WO 2005/039492, WO2006/132670, and WO 2009/095447; Fennell, B. J. et al. J. Antimicrob. Chemther. 2003, 51, 833-841). Dolastatins and auristatins have been shown to interfere with microtubule dynamics, thus disrupt cell division (Woyke et al. (2001) Antimicrob. Agents Chemother. 45(12):3580-3584) and have anticancer (U.S. Pat. No. 5,663,149) and antifungal activity (Pettit et al. (1998) Antimicrob. Agents Chemother. 42:2961-2965). Unfortunately, despite early enthusiasm, dolastatin 10 showed poor results as a single agent in phase II clinical trials (Shnyder (2007), supra). Certain compounds in the auristatins family have shown greater promise as clinical candidates with improved efficacy and pharmacological characteristics over the dolastatins (Pettit et al. (1995) Anti-Cancer Drug Des. 10:529-544; Pettit et al. (1998) Anti-Cancer Drug Des. 13:243-277; Shnyder (2007), supra). Various synthetic analogs of this structural type have been described (U.S. Pat. No. 6,569,834; U.S. Pat. No. 6,124,431; and Pettit et al. (2011) J. Nat. Prod. 74:962-968).
The auristatins have several properties which make them attractive for pharmaceutical development. First, these compounds are extremely potent. Second, their preparation is straight-forward because of the peptidic scaffold. Third, they possess good pharmacokinetic and metabolic profiles compared to peptides in general, or to other cancer drug classes in particular. Finally, the peptidic structure of the auristatins is similar to that of an antibody, so when these compounds are used as part of an antibody-drug conjugate (ADC), they are less likely to cause precipitation or formation of high molecular weight aggregates (Doronina et al. (2003) Nat. Biotechnology 21(7):778-784).
Potent cytotoxic and anti-mitotic compositions are highly desired for the treatment of a number of devastating disorders, including cancer. While a wide variety of auristatin analogs have been generated, many, exhibit reduced potency that limits utility in methods of medical treatment. For the foregoing reasons, while progress has been made in this field, there is a need for additional potent anti-mitotic and cytotoxic compounds having preferred characteristics that render them suitable for the treatment of a variety of disorders, including cancer. The present disclosure fulfills these needs and provides further related advantages.